Hormones and aggression in childhood and adolescence

This review is a survey on recent psychobiosocial studies on association between hormones and aggression/violence in children and adolescents, with a special focus on puberty, given the rapid changes in both hormones and behavior occurring during that developmental period. Since it cannot be assumed that all readers have much background knowledge, it inevitably begins with some comments about the concept and multifaceted nature of aggression, as well as with a brief reminding about hormone candidates to be linked to aggression during human development. Then, we finish off with the status of its knowledge in today’s science, tackling in a systematic way with the main data published, hormone by hormone. The origin of the gender-based differences in aggression must lie in neuroendocrinological events occurring during prenatal life or early in postnatal life. A complex and indirect effect of testosterone on aggression is proposed. A low HPA axis activity seems associated with chronic aggressive and antisocial behaviors. It is also suggested that early adrenal androgens contribute to the onset and maintenance of persistent violent and antisocial behavior, and that it begins early in life and persists into adulthood, at least in young boys. There are also some studies suggesting an association between aggression and some pituitary hormones in children, even if present data are still far from being consistent. The hormone-aggression link during development thus is not consistently reported. There can be an indirect relation in three ways: hormones can be involved in the development of aggression as a cause, as a consequence, or even as a mediator. Psychosocial factors may influence the causation and progression of violence in children through hormonal action

The usefulness of distinguishing types of aggression by function

Far from being a universally defined notion, aggression is a changing and multifaceted phenomenon encompassing various concepts. There is no consensus as to how different types of aggression should be classified: multiple ways of doing so using a variety of criteria exist in the scientific literature. Some scientists categorise aggressive acts according to how they are expressed, while others prefer to look at motive, function, purpose and objective. Despite the claim of some authors that distinguishing between different types of aggressive acts is not always productive, categorising these according to different purposes and objectives can be very useful, both for developing theory and because such an approach serves forensic practice as well as preventive and therapeutic interventions, as these focus on the propensities and personality of the individual. Furthermore, given that the main functional classifications analysed show a common tendency to dichotomise, it would seem appropriate for their terminology and some of their measurement instruments to be standardised

Biology Does Not Condemn Humanity to Violence

A brief history of the preparation of the Seville Statement on Violence (SSV) and a short exposition of its propositions are provided. The SSV was originated by ISRA (International Society for Research on Aggression), a UN-Committee launched in the late seventies of the past century. Which were the main reasons urging us to elaborate the Statement, which difficulties were found on the way and how was that first ‘scientific’ step towards peace finally achieved? Its final product, elaborated by more than twenty scholars from different scientific disciplines and from all continents, was presented in Seville in 1986, at the VI Coloquio Internacional sobre Cerebro y Agresión (CICA). Three years later, it was endorsed by the 25th General Conference of UNESCO, in Paris. Its main message is that violence and war are not genetically unavoidable, and that human nature does not oblige us to behave violently.U članku je opisana povijest pripreme Seville Statement on Violence - SSV (Seviljske izjave o nasilju, op. ur.) i ukratko su izložene najvažnije tvrdnje. Seville Statement on Violence je nastala zahvaljujući International Society for Research on Aggression ISRA (Međunarodnom društvu za istraživanje agresije, op. ur.), UN-ovog odbora koji je pokrenut krajem sedamdesetih godina prošlog stoljeća. Koji su glavni razlozi koji su nas potakli da obrazlažemo Izjavu, koje poteškoće su se pojavile i kako je postignut prvi ‘znanstveni’ korak prema miru? Konačni zaključak koji je razmotrilo više od dvadeset znanstvenika iz različitih znanstvenih disciplina i sa svih kontinenata, predstavljen je na VI. Coloquio Internacional sobre Cerebro y Agresión - CICA (Međunarodni simpozij o mozgu i agresiji) u Sevilli 1986. godine. Tri godine kasnije zaključak je potvrđen na 25. Općoj konferenciji UNESCO-a u Parizu. Njegova glavna poruka je da nasilje i rat nisu genetski neizbježni i da nas ljudska priroda ne prisiljava na nasilno ponašanje

Attitudes toward conflict and aggression

Depto. de Psicobiología y Metodología en Ciencias del ComportamientoFac. de PsicologíaTRUEpu

Aggression, and some related psychological constructs (Anger, Hostility, and Impulsivity): comments from a research project

The purpose of the present study was: first, to offer a few theoretical considerations on the concept of human aggression and its main types; and second, to analyse the relationship between those types of aggression and other related psychological constructs, such as anger, hostility, and impulsivity, summarizing the main empirical results of our research in progress. In order to assess their eventual correlations, several self-report techniques were compared: a) AQ, used to measure several kinds of aggression, anger, and hostility; b) CAMA, a questionnaire already used in a variety of cultures, for measuring attitudes toward interpersonal aggression in different instrumental and hostile situations; c) ASQ, an instrument for measuring experienced anger and its expression in assertive or aggressive ways; and d) BIS, used to prove three impulsiveness sub-traits: motor, attentional, and non-planning impulsiveness. The different definitions of aggression may be grouped according to whether the primary goal is distress or harm, focusing primarily on the objective infliction of harm, or on the subjective intention of harming. Most classifications in the literature show two kinds of aggression, even if different names are used: Hostile Aggression (among other names it is also known as 'reactive, impulsive, or affective') is an act primarily oriented to hurt another individual; and Instrumental Aggression (also known as 'proactive, premeditated, or predative') is a means or tool for solving problems or for obtaining a variety of objectives. As predicted, there was a positive correlation between experience and expression of anger. Anger involved physiological arousal and prepared for aggression. Anger and impulsiveness were also positively correlated with hostile aggression, but not with instrumental aggression. In the case of impulsiveness, non-planning impulsiveness was positively correlated with some situations related to hostile aggression, such as emotional agitation or lack of communication, but not with instrumental one

Quiescent times in gamma-ray bursts: II. Dormant periods in the central engine?

Within the framework of the internal-external shocks model for gamma-ray bursts, we study the various mechanisms that can give rise to quiescent times in the observed gamma-ray light-curves. In particular, we look for the signatures that can provide us with evidence as to whether or not the central engine goes dormant for a period of time comparable to the duration of the gaps. We show that the properties of the prompt gamma-ray and X-ray emission can in principle determine whether the quiescent episodes are due to a modulated relativistic wind or a switching off of the central engine. We suggest that detailed observations of the prompt afterglow emission from the reverse shock will strongly constrain the possible mechanisms for the production of quiescent times in gamma-ray bursts.Comment: 12 pages, 8 figures, with final revisions, MNRAS in pres

Discovery of planetary nebulae using predictive mid-infrared diagnostics

We demonstrate a newly developed mid-infrared planetary nebula (PN) selection technique. It is designed to enable efficient searches for obscured, previously unknown, PN candidates present in the photometric source catalogues of Galactic plane MIR sky surveys. Such selection is now possible via new, sensitive, high-to-medium resolution, MIR satellite surveys such as those from the Spitzer Space Telescope and the all-sky Wide-Field Infrared Survey Explorer (WISE) satellite missions. MIR selection is based on how different colour-colour planes isolate zones (sometimes overlapping) that are predominately occupied by different astrophysical object types. These techniques depend on the reliability of the available MIR source photometry. In this pilot study we concentrate on MIR point source detections and show that it is dangerous to take the MIR GLIMPSE (Galactic Legacy Infrared Mid-Plane Survey Extraordinaire) photometry from Spitzer for each candidate at face value without examining the actual MIR image data. About half of our selected sources are spurious detections due to the applied source detection algorithms being affected by complex MIR backgrounds and the de-blending of diffraction spikes around bright MIR point sources into point sources themselves. Nevertheless, once this additional visual diagnostic checking is performed, valuable MIR selected PN candidates are uncovered. Four turned out to have faint, compact, optical counterparts in our H-alpha survey data missed in previous optical searches. We confirm all of these as true PNe via our follow-up optical spectroscopy. This lends weight to the veracity of our MIR technique. It demonstrates sufficient robustness that high-confidence samples of new Galactic PN candidates can be extracted from these MIR surveys without confirmatory optical spectroscopy and imaging. This is problematic or impossible when the extinction is large.Comment: 14 pages, 7 figures, 7 tables; accepted for publication in MNRA